Distribution of liver stiffness in non‐alcoholic fatty liver disease with higher fibrosis‐4 index than low cut‐off index

摘要

Abstract Background and Aim In the condition of high prevalence of non‐alcoholic fatty liver disease (NAFLD), a new diagnostic algorithm to efficiently identify NAFLD patients with significant fibrosis is urgently required. We evaluated the predictive ability of the fibrosis‐4 index (FIB‐4 index) for significant liver fibrosis ( F ?≥?2) in a cohort of Japanese patients with NAFLD. Methods We prospectively calculated the FIB‐4 index in patients who were incidentally diagnosed as fatty liver in medical checkups and then conducted liver stiffness measurement by vibration‐controlled transient elastography (VCTE) only in patients in whom the FIB‐4 index was more than the low cut‐off index (?1.45). Results Of the 5929 people who underwent medical checkups, a total of 1374 people were identified as having fatty liver. Among these, we performed VCTE in 106 patients in whom the FIB‐4 index was higher than 1.45. The distribution of the fibrosis stage as estimated by VCTE in the patients was as follows: F0, 52.8%; F1, 10.3%; F2, 21.6%; F3, 11.3%; and F4, 3.7%. The positive predictive value of the FIB‐4 index for detecting NAFLD with significant fibrosis was 36.6%. The minimum value of the FIB‐4 index was constant for each estimated fibrosis stage. Conclusions This is the first prospective study to evaluate the usefulness of the FIB‐4 index as the first step to screen NAFLD patients with significant fibrosis. In Japan, addition of one further step that combined with the FIB‐4 index is necessary to meaningfully reduce the number of patients needing liver stiffness measurement or liver biopsy.